RESUMO
BACKGROUND:The analysis of gas flow in upper respiratory tract of patients with obstructive sleep apnea-hypopnea syndrome contributes to further understanding the correlation of anatomical structure and function of upper respiratory tract so as to know the pathogenesis of obstructive sleep apnea-hypopnea syndrome. OBJECTIVE:To establish the three-dimensional computational fluid dynamics model of upper airway in patients with obstructive sleep apnea-hypopnea syndrome, to study the characteristics of airflow dynamics in upper respiratory tract in above patients, and to lay the foundation for further exploring the pathogenesis of obstructive sleep apnea-hypopnea syndrome. METHODS:CT scan of the upper airway was performed with a moderate obstructive sleep apnea-hypopnea syndrome patient. Data stored in DICOM format were imported in Mimics 10.01 software, and processed, and then computational fluid dynamics model was built. ANSYS ICEM CFD14.0 was used to perform the grid division of the three-dimensional model. The internal flow of upper respiratory tract was simulated by ANSYS 14.0-Fluid Dynamics, and relevant information on airflow field of upper airway was obtained. RESULTS AND CONCLUSION: The three-dimensional computational fluid dynamics model of upper airway wasestablished with 1 751 940 elements and 303 981 nodes of upper airway. The flow rate was 11.087 m/s in the lower bound of pharyngopalatiae, which was the most narrowed areas of upper airway in patients with obstructive sleep apnea-hypopnea syndrome. The three-dimensional computational fluid dynamics model of upper airway has accurately simulated biomechanical feature of human, which provides a foundation for further studying the airflow dynamics of upper respiratory tract of patients with obstructive sleep apnea-hypopnea syndrome.